This article traces the development of acoustic navigation media, or “sonar,” in the first half of the twentieth century, focusing on the relationships forged between underwater sound, electric media, and new techniques of listening. The central argument is that sonar…

This article explores the militarization of everyday life through the emergence of a dual-use technology, the Global Positioning System (GPS), in the 1990s and first decade of the twenty-first century. It was launched in April 2010 as a Web-based multimedia…

This article engages with three different modes of Earth observation—historical network maps, Google Earth interfaces, and fieldwork—to develop the concept of “signal territories” and elucidate a critical approach for studying U.S. broadcast infrastructure. This approach: 1) highlights physical infrastructures—technological hardware…